Starting Construction On a SIP House

My wife and I have owned 10 acres in southeastern Michigan for 10 years and this year we are building a house on this property. I, being a nerd, have been researching advances in building techniques over the years. I have been watching Structural Insulated Panels (SIPs). So we decided to go SIPs from Insulspan which had the added benefit of being a local company so transportation costs would be less. I also knew I wanted to insulate the basement we are using a pre-cast concrete wall system from Great Lakes SuperiorWalls which start out at R12.5 but can go much higher by filling the cavities with insulation when you finish the wall.

We worked with Josh Seiser at Super Build Systems to come up with a plan that maximizes the space and use of panel material. We are going with a story and a half Cape Cod style house. While there are some spaces on the second floor at the eves with a low overhead they are within the insulated envelope of the house so they provide great storage options basically for free. Josh and his crew are also putting up the shell of the house. (Videos at www.youtube.com/my10acres.)

There are engineering advantages to using a panel, when the skin is part of the structure it is much stronger. There are only splines (think 2x6 studs) at the joints between the panels and around every opening.A normal stud wall has a stud every 16 inches, which is a path for thermal transfer; a SIP structure has many fewer of these.

SIPs also have very low air infiltration (no drafts). Air cannot go through a panel because the foam core simply does not air through. Super Build Systems also glues all joints which also blocks air infiltration at the joints between panels.

While the initial costs of SIPs are higher the energy savings will continue to pay you back for the life of the house. If you have some flexibility with your house plan so it can be optimized for the panel material the cost doesn’t have to be much more than conventional building. Think about it if you are in the market for a new house or even a major addition. Notice how thick the roof panels are.

A key thing about SIP houses is to have ventilation that you control, bringing fresh air into the house. So we will be installing a heat recovery ventilator. Also as I understand it the Styrofoam insulation is very low off-gassing.

Sheila Murdock

1/6/2012 11:12:06 PM

Anyone know what the insulation is made of and if there are any side effects of inhaling anything that out-gases from the material?

Brent Pieczynski

1/6/2012 9:27:42 PM

Difficulty finding people to do this is a difficulty in Alaska yet insulating foam sprayed on the outside of a building is more common.

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